This section provides background information to facilitate a better understanding of the various aspects of the disclosure. It should be understood that the statements in this section of this document are to be read in this light, and not as admissions of prior art.
Agricultural harvesting machines such as combine harvesters are used to reap, thresh, and winnow grain crops such as wheat, rye, barley, corn, soybeans, oats, flax, sunflower, and canola. More specifically, combine harvesters are used to cut grain crops at the base, separate the grains from the remainder of the plant (the chaff), and sort the grain from the chaff. These machines require special adaptations to accommodate specific crops, navigate through field landscapes, and resist damage from the crops, stone, and the elements; especially moisture and high temperature which can lead to the degradation of the machine's rubber components.
Generally harvesting machines gather crops using a header having crop dividers which define crop gathering gaps as the machine moves through a field. The gathered crops are pushed by a reel into a cutter bar, which runs the length of the header and is equipped with teeth made of metal or plastic to cut crops at their base. Headers may have a rigid or flexible header platform depending upon the operator's needs. Flexible header platforms, or “flex headers” have a cutter bar which is capable of flexing over uneven terrain. Machines using flex headers are most often used to cut soybeans, whereas conventional header platforms have a rigid cutter bar and are most often used to cut cereal crops. Freshly cut crops fall behind the cutter bar and onto a plurality of side by side draper belts which are wrapped around parallel spaced rollers. Draper belts function primarily to consolidate crops and move the crops from the header towards the threshing drum. Crops are fed into the threshing drum by spinning augurs. Inside the threshing drum, the grains are shaken from the plant. Grains fall through sieves into a grain collecting tank, and the plant waste, or chaff, is moved to the back of the machine by conveyor belts for later disposal.
Draper belts are an important component of agricultural harvesters. These belts are often subject to prolonged sun exposure, high temperatures, cold temperatures, rain and moisture, dirt and stone, as well as excessive friction from the moving machinery and crops. Furthermore water is known to migrate through the rubber belts carrying corrosive elements and salts which degrade the belt. Draper belts are typically called upon to operate for long periods of time. For these reasons, it is necessary that draper belts be specially adapted to maximize durability and service life, and it is desirable for such adaptations to be cost effective.
Some improvements in reducing the susceptibility of draper belts to damage have been made and are reported in the prior art. U.S. Pat. No. 8,544,250 discloses a draper platform having a center endless belt conveyor that is supported on and between first and second adjacent support arms. The endless conveyor belt has laterally extending cleats bonded thereto that engage the crop and assist in dragging the crop along the belt. U.S. Pat. No. 7,543,428 shows a seamless draper belt formed from an elongated flat base structure of fabric and rubber, and transverse cleats having a structural core embedded in rubber are connected to the base. Cleats formed from a structural core embedded in uncured rubber are positioned on one face of the base structure. The molding and curing of the rubber over the cleat cores and adjacent base structure is done leaving a portion of the base structure adjacent the first and second ends being uncured. The uncured ends are then overlapped and cured to form an endless seamless draper belt.
U.S. Pat. No. 6,817,166 describes a feed draper carrying cleats which are angled to the rollers in two sections converging to a central leading apex to reduce forces on the cleat as they pass over the front guide roller which is of reduced diameter to fit within a small space adjacent the cutter bar. Such cleats are often reinforced by a rod inside the molded material of the cleat, which is generally a resilient natural or synthetic rubber material. The draper canvas having on its outer surface a plurality of generally transversely extending longitudinally spaced cleats attached to the outer surface and extending outwardly there from for engaging the cop and providing a longitudinal force on the crop.
U.S. Pat. No. 7,478,521 discloses a cutting platform for use with an agricultural harvesting machine which includes a plurality of platform sections positioned in end-to-end juxtaposed relation to each other. At least one platform section includes a frame, a plurality of float arms movably coupled with the frame, an endless belt carried by the plurality of float arms, and a cutter bar assembly carried by the plurality of float arms and movable in a localized manner in upwards and downwards directions. The endless belt has a plurality of spaced apart cleats which do not extend to the lateral side edges thereof, allowing the belt to travel between belt guides and upper run carriers without unnecessary clearance space there between.
It is common for draper belts of the prior art to fail for one or more reasons. Frequently draper belt cleats become worn and damaged from use, and this exposes fiberglass rods within the cleats which provide the cleats with lateral support. To reduce this problem, manufacturers of agricultural machinery have redesigned combine headers and the like; however, draper belt cleats remain unusually prone to damage and wear in all known machine and header designs. Accordingly there is a need for a specially adapted draper belt having significantly more durable cleats than the draper belt cleats of the prior art.